You bring up some very, very good points.
I blame the U.S. Government for this! Congress after congress, president after president have let us down in regards to protecting American citizens from dangerous individuals coming in from South of the border. I can say, most Mexicans are not blood thirsty criminals. That said, their culture is much different. They will work the system, they will go around the system...do whatever it takes to survive. They don't care about the laws. It is about survival. Just like the middle east refugee issue, there are very dangerous hombres mixed in with those who just want to work. I mean REAL bad guyz that will shoot you and your family in order to make the next drug shipment.
We need a wall, we need it yesterday.